One who blocks or impedes the movement of an opponent.
A gatekeeper who refuses the marketer access to the person they wish to contact.
A bug or issue that prevents software from being released.
A person who blocks (stretches or moulds) hats.
A blocker bet.
Any of various medications that block (inhibit) the activity of a chemical messenger or its receptors, such as cardiac conduction modifiers (e.g., alpha-blockers), gastric acid inhibitors (H₂ histamine blockers), puberty blockers, and others.
A close-fitting rectangular glove worn by a goalie in multiple forms of hockey.
One who prevents another user from contacting them electronically.
An application that stops / impedes unauthorised access to a programme.
A playing card, needed by one player, that is held by another.
A side, party (e.g. a team or armed force) seen as adversary, enemy etc. opposite one (or more) other(s), as in a battle or team sports competition.